Method for deeply treating waste water containing aldehyde through waste aldehyde pretreatment-photo-catalytic oxidation

The invention discloses a method for deeply treating waste water containing aldehyde through waste aldehyde pretreatment-photo-catalytic oxidation. An adjusting system, a reaction system, a photo-catalysis system and a settling pond are adopted, the systems are sequentially connected through process pipes, flanges and lift pumps, and ultrasonic scale prevention devices are arranged between the connection pipes of the systems. The adjusting system can automatically adjust the flow of the waste water containing aldehyde according to the set temperature and the set pH value, and then the waste water flows to the reaction system. The reaction system comprises a U-shaped mixing reactor with the inner cavity wall provided with flow diversion mixing blades, and a formaldehyde detector. Formaldehyde enters the photo-catalysis system after condensation saccharification. The photo-catalysis system is composed of a quartz pipe externally provided with an ultraviolet light generator and internally provided with a catalyst, and a formaldehyde detector. Formaldehyde continues the catalytic reaction, the concentration of formaldehyde of outflow water is lower than the required value 50 mg/L, and the water flows to a biochemical treatment system after settling treatment. The method has the advantages that operation is simple, operating cost is low, and social benefits and economic benefits are high.